Hebrews 1:3

who being the splendour of his glory, and the very impress of his substance, and upholding all things with his powerful word, by himself having effected the cleansing of our sins, he sat down at the right hand of Majesty on high;

Hebrews 9:7

but into the second once in every year entered the high-priest alone, not without blood, which he offered for his own inadvertencies, and for those of the people:

Hebrews 9:22-23

And almost all things are purified by blood according to the law, and without effusion of blood there is no remission of sin.

Hebrews 9:25

and not that he should often offer up himself in sacrifice, as the high-priest enters every year into the holies with blood not his own,

Treasury of Scripture Knowledge

Summary

And Aaron shall make an atonement upon the horns of it once in a year with the blood of the sin offering of atonements: once in the year shall he make atonement upon it throughout your generations: it is most holy unto the LORD.

Bible References

Aaron

Hebrews 1:3
who being the splendour of his glory, and the very impress of his substance, and upholding all things with his powerful word, by himself having effected the cleansing of our sins, he sat down at the right hand of Majesty on high;
Hebrews 9:7
but into the second once in every year entered the high-priest alone, not without blood, which he offered for his own inadvertencies, and for those of the people: